AB0716 Characteristics of 4 cases of PL - 7 positive antisynthatase syndrome: interstitial lung disease being a more common feature then myositis
Authors: C. Rosa, K. Chaudhuri, G. Kasavkar, A. Price-Forbes, S. Banerjee
Journal: Annals of the Rheumatic Diseases (2022)

Background Anti synthetase syndrome is a heterogeneous group of auto immune diseases characterised by antibodies against aminoacyl t RNA synthetase, associated with interstitial lung disease, myositis, arthritis and Raynaud’s phenomenon. Anti PL 7 antibody is rare, present in only 1-4% patients with anti synthetase syndrome. Objectives To describe clinical characteristics PL – 7 positive patients with antisynthatase syndrome. Methods In this retrospective study, cohort of patients with inflammatory myositis were screened for anti PL-7 antibody positivity and 4 cases were detected. Diagnosis was made based on either 2017 EULAR/ ACR classification criteria and/ or Bohan and Peter criteria. [1, 2] Clinical manifestations, investigations including antibody profile, treatment and treatment response were described. Results Of the 4 patients, 3 were female and age of onset varied from 36 to 69 years. Only 1 patient presented with proximal muscle weakness while three patients with dyspnoea. Joint involvement and Raynaud’s phenomenon was present in 2 patients. Two patients had scleroderma spectrum manifestations. Three patients had elevated CK during the disease course with maximum values being 228, 594 and 1200 with only one having muscle weakness. One patient had dermatomyositis and 2 patients had mechanic‘s hand. HRCT patterns were usual interstitial pneumonia(UIP), nonspecific interstitial pneumonia(NSIP) and fibrosing NSIP with organising pneumonia. Three patients had anti Ro antibodies. All patients were treated with steroids, one each received Cyclophosphamide and Azathioprine initially however all the patients ended up with Mycophenolate mofetil—which controlled disease effectively without flare. Table 1. Patient 1 Patient 2 Patient 3 Patient 4 Age at onset 69 years 52 years 36 years 55 years Gender Male Female Female Female Presentation Shortness of breath Shoulder weakness Arthritis and shortness of breath Shortness of breath Muscle No weakness No weakness No weakness Maximum CK (U/L) 228 594 1200 105 Raynaud’s Present Absent Present Joint Arthritis - present Absent Present Absent Skin Skin tightnessScelrodactylyNail fold capillaries dilation Absent Skin tightnessScelrodactylyNail fold capillaries dilationMechanic’s hands, facial pigmentation Mechanic’s hand Lung Present Absent Present Present Antibodies ANA+Anti Ro+PL - 7 + ANA+, anti Ro &amp; La +, anti Ro52+PL – 7+ ANA negativeanti Ro52+PL – 7+ ANA negativePL – 7 + HRCT UIP No ILD NSIP Fibrosing NSIP, COP Lung function FEV1 53% Not available FEV1 36% FEV1 65% FVC 47% FVC 35% FVC 82% FEV1/FVC 113% FEV1/FVC 103% FEV1/FVC 83% DLCO 34% DLCO 49% DLCO 50% EMG Not done Chronic myopathy Not done Not done Muscle biopsy Not done Not available Not done Not done Treatment Prednisolone andIV cyclophosphamide initially (side effects)Later on Mycophenolate MofetilStable disease PrednisoloneInitially AzathioprineLater MMF due to relapsing disease while of AZA MMF and Prednisolone—clinical response Prednisolone and Mycophenolate-response with normalisation of PFT Pulmonary hypertension Present Absent Present Absent Conclusion In Anti PL – 7 positive patients, interstitial lung disease is much more common than myositis. Mechanic’s hands and scleroderma overlap appear to be a common association. Additionally, antibody positivity with Anti Ro/Ro52 was also noted. One patient had features of dermatomyositis including facial rash which is extremely rare for PL7. All of these patients responded very well to Mycophenolate. References [1]Lundberg IE, Tjärnlund A, Bottai M, et al. 2017 European League Against Rheumatism/American College of Rheumatology classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups [published correction appears in Ann Rheum Dis. 2018 Sep;77(9):e64]. Ann Rheum Dis . 2017;76(12):1955-1964. doi:10.1136/annrheumdis-2017-211468 [2]Bohan A, Peter JB. Polymyositis and dermatomyositis (first of two parts). N Engl J Med . 1975;292(7):344-347. doi:10.1056/NEJM197502132920706 Disclosure of Interests None declared